BBC tech editor Rory Cellan-Jones tweeted a picture sent to him by a doctor (posted above) reporting “what a London GP sees when trying to connect to the NHS network.”

Hospitals affected stay they are shutting down all computer systems as a protective measure.

NHS Digital, which runs the booking platform, claimed there was no evidence patient data has been compromised. It said the attack was believed to be carried out by the malware variant Wanna Decryptor and it is now working with the National Cyber Security Centre, the Department of Health and NHS England over the attack.

The BBC reports that up to 25 NHS organisations and some GP practices have been affected.

Britain’s National Health Service is a treasured institution and is free for anyone to access, but has ben hit by substantial budget cuts and clearly runs inadequate security systems.

It’s too early to tell, but the attack may be part of a much larger one globally.

A malware researcher at Avast is reporting on Twitter that there have been 36,000 detections of Wanna Decryptor globally including in Russia, Ukraine and Taiwan.